Levels of Prostaglandins F2α and E2and Thromboxane B2In Joint Fluid in Rheumatoid Arthritis

Abstract

Prostaglandin F₂α (PGF₂α), prostaglandin E₂ (PGEg) and thromboxane B₂ (TXB₂) levels were determined by radioimmunoassay (RIA) in knee joint fluid in two groups of patients with classical or definite rheumatoid arthritis (RA). One group had no treatment for one week prior to the study. The second group consisted of patients who developed acute exudative arthritis despite the use of various non-steroidal anti-inflammatory drugs (NSAID). The main metabolites of PGF₂α in plasma and urine were measured in the untreated group. The conclusions to be drawn from this study are: 1) Treatment with NSAID effectively lowers PGF₂α and PGE₂ and TXB₂ levels in joint fluid. 2) Signs and symptoms of arthritis may persist in spite of lowered levels of PGF₂α and PGE, in the joint fluid. 3) The main metabolites of PGF₂α in plasma and urine are above the low-normal limit in untreated patients. 4) The ratio TXB₂/PG was low in untreated patients, suggesting that the thromboxane pathway is quantitatively minor in rheumatoid joint inflammation.